Device for classifying objects according to weight



March 18; 1.947.

F. W. GILCHRIST EIAL DEVICE FOR CLASSIFYING OBJECTS ACCORDING PO-WEIGHT 5 Sheets-Sheet 1 Filed Sept. 28, 1943 GULATIN TRANJ.

Fred W 6770/7/75? Dona/d 15. A endafl Faber? Q [Brad/6 y INVENTORS iziwzzg/wzl ATTORNEYS Mandi-l3, 7- F. w. GILCHRIST ETAL 2,417,642

DEVICE FOR CLASSIFYING OBJECTS ACCORDING TO WEIGHT Filed Sept. 28, 1943 5 Sheets-Sheet 2 Robe/"7 Q firaa ey uvmvrozzs ATTORNEYS March 1947- F. w. GILCHRIST ETAL 2,417,642

DEVICE FOR CLASSIFYING OBJECTS ACCORDING TO WEIGHT Filed Sept. 28, 1943 5 Sheets-Sheet 3 3 e Fred W ave/ms? 0000/0 Z3. /1e/70c7// D Robe/f 0. Brad/6y v INVENTORS ATTORNEYS March 18, 1947. F. w. GILCHRIST ETAL 2,417,642

DEVICE FOR CLASSIFYING OBJECTS ACCORDING TO WEIGHI Filed Sept. 28, 1943 5 Sheets-Sheet 4 U o M 4 f m 5 m m nm E T6 1 CH... T A A HE R V E E L. D U 5 CONTACT n3 CLOSED {comma :27 CLOSED svvn'cu ae- CONTACY CLOSED Aolzerr C2 Brad/6y JNVENTORS ATTORNEYS March 18, 1947.

F. w. GILCHRIST EI'AL 2,417,642

DEVICE FOR CLASSIFYING OBJECTS ACCORDING TO WEIGHT Filed Sept. 28, 1943 5 Sheets-Shoat 5 r IIIIIIIIIII'IIIIIIQ 1 I n ERR Fred W 6770/2/73? Dana/0 5. hendafl Robe/*7 0. Brad/6y mmvrozzs Patented Mar. 18, 1947 DEVICE FOR CLASSIFYING OBJECTS ACCORDING TO WEIGHT Fred W. Gilchrist, Donald B. Kendall, and Robert 0. Bradley, Toledo, Ohio, assignors to Toledo Scale Company, Toledo, Ohio, a corporation of New Jersey Application September 28, 1943, Serial No. 504,140

6 Claims.

thesedevices consist of means for automatically loading the object onto the scale, operating a selecting mechanism according to the indicated weight, then unloading the object into the selected chute. The speed of operation of these devices was limited by the time required for the scale to come to rest.

The object of the present invention is to pro v a ei g scale for classifying objects by weight which is capable of high speed operation and high accuracy.

Another object is to provide means for loadin and unloading objects onto and from the scale load receiver in a minimum length of time, without excessively disturbing the scale lever,

A still further object is to provide a scale which will weigh an object accurately without coming to rest.

These objects and others apparent to those skilled in using devices of this class are attained in the weighing and classifying scale shown in the accompanying drawings in which:

Fig. I is an exterior view of the device.

Fig. II is a schematic wiring diagram of the incorporated electrical equipment. v

Fig. III is a front elevationalview, parts being broken away, and parts being shown in section, of the scale with its cover removed.

Fig. IV is an end elevational view as seen from I the right side of Fig, III.

Fig. V is a fragmentary view taken along the line VV of Fig, IV.

Fig. VI is a timing diagram, illustrating the sequence of operations.

Fig. VII is an enlarged fragmentary view taken along the line VIIVII of Fig. IV.

liigVHI is a detailed view of the light interceptor.

Fig. IX is a fragmentary view taken along the line IX-IX of Fig. VII showing the lever stop.

Fig. X is a plan view of the loading mechanism taken along the line XX of Fig. IV.

Fig. XI is a fragmentaryelevational view of the loading mechanism taken along the line XI-X[ of Fig. X.

Fig. XII is a fragmentary view of a portion of the loading mechanism taken along the line XIIXII of Fig, IV.

These specific drawings and accompanying description are intended merely to illustrate the invention and not to impose limitations on the accompanying claims.

The device completely enclosed and ready for use is shown in Fig. I. Objects to be weighed are fed down a supply chute l0, and after weighing leave via one of a number of discharge chutes H, one chute accommodating the under weight, another the correct weight, and a third the overweight speclmens. A switch I 2 conditions the circuits for either continuous automatic operation or intermittent operation for testing purposes wherein each weighing cycle is initiated by pressing a push button l3.

Referring to Fig, III a pedestal it is erected on a substantial main base it and is provided at its upper end with a bearing bracket is having agate bearings ll suitably embedded therein.

A lever 58, supported on the agate bearings H by a knife edge is, comprises a slender tubular lever arm 26, a depending stud 25 carrying an adjustable pendulum Weight 22 and a horizontally extending stud 23 fitted with a balance weight M. The free end of the tubular lever arm 20 carries a load receiver 35 and a light interceptor 26.

The lever i8 is normally held at the upper end of its travel by a solenoid operated latch 21 (Fig. VII) engaging a cam surface28 of the load receiver 25. The upward travel of the lever arm 20 is limited by a notched stop member 29 (Figs. VII and IX). Thus the latch 21! and the stop 29 combine to definitely locate the lever 88 at the upper limit of its travel.

Electrical indication of lever movement is provided by a photoelectric system comprising a light source and a photocell, The light source consists of a lamp bulb 30 and a cylindrical focusing lens 3| adjustably mounted in a tubular lamp housing 32 clamped to a subbase 33. A photocell 34 receiving light from the light source through a slot 35 in an enclosing light shield 36 is also mounted on the subbase 33 in spaced relation to the light source. The subbase 33 is adjustably supported on a vertical bracket 3'! bolted to the main base l5.

These elements are so adjusted that the light interceptor 26 passes between the light source and light shield 36 adjacent the latter. Light rays emanating from the lamp 30 are sharply focused on the interceptor 26 by the lens 3| and in the absence of the interceptor 26 pass through the slot 35 to the photo cell 34. The light interceptor 26 is provided with spaced vanes 38 and 39 (Fig. VIII) to interrupt the light beam when the lever I8 occupies certain predetermined positions.

The automatic loading mechanism is mounted upon a standard 48 bolted to the main base I5. Objects to be weighed, shown in Fig. XI as cylindrical projectiles, are fed into the supply chute I8 either manually or automatically. From this they proceed via a helical spring chute 4|, an

escapement 42, and a loading slide 43 to the load receiver 25 supported on the lever I8. The escapement 42 consists of a recessed block 44 adjustably mounted on the upper end of a vertical reciprocatory member 45 whose lower end is transversely slotted to receive a roller 46 journaled on a crank pin 41 extending from the side of a gear wheel 48. When the recessed block 44 is in the upper position the recess aligns axially with the helical spring chute 4| so that objects to be weighed may successively slide from the chute 4| into the recess. A shaped guard plate 49 prevents the object from rolling out of the recess until the block 44 moves to its lower position. As the recess in the block 44 drops below the adjacent surface of the guard plate 49 the object rolls from the recess onto the loading slide 43.

The top of. the standard 48 under the escapement is provided with a V-shaped trough 58 of which the load receiver 25 forms a continuation. The loading slide 43 which slides in ways recessed in the top of the standard 48 parallel to and over the trough 58 has near its forward end a slot which when the slide 43 is retracted allows objects to drop from the escapement 42 to the trough 58. Lips 52 at the ends of the slot 5| transmit slide motions to the object. Another lip 53 at the tip of the slide 43 pushes the previously weighed object from the load receiver 25 as the slide 43 moves forward to position the next object thereon.

To retract the slide 43 its rear portion is slotted and provided with a roller 54 which engages a cam 55 fixedly mounted on a shaft 56 journaled on the standard 48. The shaft 56 is driven by a motor 51 acting through gears 58. The slide is pulled forward quickly when the roller 54.1eaves 'the high spot of the cam 55 by a pair of tension springs 58 acting between a crosshead 68 mounted on the rear end of the slide 43 and a similar crosshead 6| attached to the standard 48. The forward motion of the slide is arrested by stops 62 engaging the crosshead 68 when the object between the slot lips 52 is centered on the load receiver 26.

The escapement driving gear 48 is driven from a gear 63 on the shaft 56 through idler gears 64 r and 65 mounted on a strip 66 pivoted on a pin 61 which also journals the gear wheel 48. The strip 66 is yieldably held, by means not shown, in position with the idler gear 64 in mesh with the driving gear 63. If for any cause the escape-' ment 42 should jam, the strip 66 moves upwardly disengaging the gear drive, without damaging any of the structure.

As the weighed objects are pushed from the load receiver 25 they are directed to the proper one of the discharge chutes II by guides 68 erected on a plate 68 which is attached to selector frame 18. The selector frame 18 is pivotally supported on a horizontal axis near the top of a post 1| erected on the main base l5. Rotary motion of the frame 18 is limited by depending fingers 12 straddling a lug 13 extending from the side of the post 1|. The selector frame 18 is rocked on its axis by selective operation of a pair of solenoids 14 and 15 acting through links 16 connected to arms 11 extending horizontally from the sides of the frame 18. Preloaded springs 18 included in the links 16 allow the solenoid armatures 19 and 88 to overtravel slightly after firmly positioning the selector frame against the lug 13. With the solenoids 14 and 15 deenergized the selector frame 18 is returned to and maintained in its mid position by a compression spring 8| (Fig. 111) surrounding the telescoping junction of tubes 82 and 83 pivotally attached to the selector frame 18 and the lever supporting pedestal I4 respectively. The compression spring 8| is held and acts through retaining keys 84 and 85 inserted through registering slots in the tubes 82 and 83. Since the ends of the slots register only when the selector frame 18 is in its midposition any movement of the selector frame 18 will cause telescoping motion of the tubes 82 and 83 and corresponding compression of the spring 8|. Thus is attained a yieldable coupling having a definite midposition.

A suitable cover 86 overlies the selector frame 18 and guides 68 to deflect the weighed objects downward into the chute.

The electrical and mechanical operations are synchronized by a pair of switches 81 and 88 operatedby suitable cams 89' and 98 mounted on the shaft 56.

In operation the motor 51 rotates the cam 55 counterclockwise from the position shown in Fig. XI allowing the loading slide 43 to rapidly move forward, thus pushing the previously weighed object off and positioning the next one on the load receiver 25. After allowing time for the object to come to rest the latch 21 is withdrawn releasing the lever I8 which immediately swings downward. As the lever I8 moves down the object is carried below the slide lips 52 and the motor 51 through the cam 55 then retracts the slide 43.

At the bottom of the swing the vane 38 may approach without intercepting the light beam from the light source to the photocell, or it may intercept it momentarily, or it may swing past it thus intercepting the beam momentarily on both the downand return stroke. The first condition occurs if the object is under weight, the second if it is of correct weight, and the last, the double interruption, if it is overweight.

When the slide retracting cam 55 has completed a revolution and returned to the position shown in Fig. XI the switch 81 actuated by the cam 89 on the shaft 56 is operated to stop the motor 51. A short time later, as the lever I8 completes its swing, the vane 38 intercepts the light, to initiate the latching of the lever I8 and the reenergization of the motor 51 to start the next cycle.

Meanwhile the selector frame 18 has been positioned according to the photocell signals received at the bottom of the lever swing to direct the weighed object to the proper one of the discharge chutes II when it is pushed off the load receiver The electrical controls to obtain this automatic operation are shown schematically in Fig. 11.,

comprising the lead I01, a lead I08, 8. photocell amplifier I09, a lead 0, and a portion of the lead I04.

The photocell 34 and light bulb 30 are connected'by leads III and H2 and leads H3 and Ill. respectively to the amplifier I09. The output current of the photocell amplifier flows through a lead II5, the coil of a relay H6, and a lead II1 to energize the relay II6 when the photocell is light. For normal automatic operation the manual-automatic switch I2 is closed to connect a lead I I8 from the supply lead I to a lead II9. Current then flows from the supply lead I05 through the lead II8, the switch I2, the lead H9, a. branch lead II9a, normally closed contacts I20 of a relay I2I, leads I22a and I22, the motor 51 and a lead IBM to the return lead I04. Current also flows from the lead II9 through a branch lead II9b, normally closed contacts I23 oi the cam operated switch 81, a lead I24, a

leads I I9a and I22a is also open. The motor 51 switch 81 opening the contacts I23 and closing the normally open contact I21. Current then flows from the energized lead I I9 through the lead II9b, the now closed contact I21 of the switch 81, leads I28, I28a, and I281), the coil of the relay I2I and a lead I 040 to the return lead I04. Relay I2I now energized opens its contacts I20 thus breaking the circuit to the motor 51 through leads II9, II9a, contacts I20, leads [22a and I22. The motor 51 does not stop since the switch 81 by opening the contacts I23 broke the circuit from the energized lead II9 through the lead 91), contacts I23, the leads I24 and I24a, the coil of the relay I25 and leads I 04b and IBM to the return lead I04. The relay I25 thereby deenergized closes the contacts I26 and current flows from the energized lead II9 through the leads II9c, the contacts I26 and the leads I22!) and I 22 to run the motor 51.

Current also now flows from the energized lead II9 through the lead II9b, contacts I21 of the switch 81, the leads I28 and I28a, a lead I28c, the lever latch release solenoid I29, and a lead I04d to the return lead I04.

The solenoid I29 then withdraws the latch-21 and the lever I8 starts its swing. As the vane 38 of the interceptor 26 leaves the light beam, light enters the photocell 34 and the associated relay H6 is accordingly energized and closes contacts I30. light current may flow from the supply lead I05 through a branch lead I05a, contacts I 30 of the relay II6 to leads I28b and I28c to energize the relay I2I and the latchsolenoid I29.

The motor 51, now energized through the contacts I26 of the relay I25, continues to rotate the cam 89 until the switch 81 returns to its normal position opening the contacts I21 nd closing the contacts I23. Closure of the switch contacts I23 energizes the relay I25 through leads I24 and I24a, causing it to open its contacts I26, thus breaking the, branch'circuit through leads H90 and I22b to the motor 51. Since normally the photocell is also light at this time the relay I2I I .is energized so the other motor circuit through Thus, whenever the photocell 34 'is' therefore stops with the switch 81 in its normal position.

As the lever I8 approaches its upper position the vane 38 intercepts the light beam and thus, by deenergizing the relay II6, opens the contacts I30. Since the contacts I21 of the switch 81 are open, the opening of contacts I30 interrupts the current flow through the leads I28c and I28b to the latch solenoid I29 and the relay I2I. The latch 21 thereby released engages the surface 28 of the load receiver 25 to lock the lever I8, while the relay I2I closes its contacts I 20 to energize the motor 51 from the energized leads I I9 through leads Il9a, contacts I20 and leads I22a and I22, thus starting the next cycle.

Returning to the portion of the cycle when the lever I8 approaches the bottom of its swing and assuming the object being weighed is overweight, the vane 39 of the interceptor 26 interrupts the light beam thus deenergizing the relay H6, and current flows from the energized lead II9, through the leads I I 9b, contacts I3I of the switch 88, leads I33 and I33a, contacts I34 of the relay I25, a lead I35, contacts I36 of the relay II6, leads I31 and I31a, the coil of a relay I38 and a lead I04e to the return lead I04. Relay I38, thus energized, by closing its contacts I39 cornpletes a holding circuit from the lead I33 through a lead I331), contacts I39, and the lead I31a to energize the relay I38 independently of the relay II6. As the lever I8 continues its downward swing the relay H6 is energized as light again enters the photocell 34 and current then flows from the now closed and energized contacts I39 through the leads I31a and I31, contacts I40 of the relay II6, leads MI and I4Ia, the coil of a relay I42 and a lead I 04 to the return lead I04. The relay I42, by closing its contacts I43 establishes a holding circuit from the previously energized relay I38 through the leads I31a, I312) and the contacts I43. The relays I38 and I42 are now held in by current flowing through the switch 88 and their own holding contacts I39 and I43.

On the upward swing of the lever I8 the vane 39 again interrupts the light to deenergize the relay H6. This time, since relays I38 and I42 are still held in, current flows from the lead I4 Ia through the lead MI, the now closed contacts I44 of the relay H6, a lead I45, contacts I48 of the relay I25, 2. lead I41, the coil of a relay I48 and a lead H349 to the return lead I04. The relay M8 closes its contacts I49 to establish a holding circuit from the lead I4I, energized from the relay I42, through lead Hill) and contacts I 4-9 to the lead I41 to hold relay I48 energized independently of the light controlled relay II8.

The next energization of the relay II6 as the vane 39 leaves the light beam has no effect upon the circuits other than to hold the relay I2I and latch solenoid I29 energized as the cam 89 returns the switch 81 to its normal position with contacts I 21 open when the lever is about half way up on its return swing. The contacts I23, closed by operation of the switch 81, allow cur rent to flow from the energized lead H9, through leads I24 and I24c, contacts I50 of the now closed relay I48, a lead I5I and the solenoid 15 to the return lead I04. The solenoid 15 thereupon positions the selector plate- 69 to direct the object into the overweight group.

If the object is under weight the lever does not swing far enough to cause the vane 39 to interrupt the light beam. Thus there are no operations or the relay II8 before the cam 89 returns the switch 81 to its normal position thereby energizing relay I25 toopen its contacts I28, I34, and I48. The open contacts I34 and I48 prevent operation of any of the relays I38, I42 or I48. Therefore, when the contacts I23 of the switch 81 close current flows from the energized lead II9 through the contacts I23, leads I24 and I24b, the normally closed contacts I52 of the relay I38, a lead I53 and the solenoid 14 to the return lead I04. The solenoid 14 thereupon positions the selector to direct the object into the underweight group.

If the object is of the correct weight the vane 39 will interrupt the light beam once at the bottom of its swing and in the manner described will energize the relays I38 and I-42. There being no more light interruptions before the switch 81 is returned to its normal position, the cycle ends with the relays I38 and I42 energized and the relay I48 deenergized. Therefore the circuits to the solenoids 14 and are open and the selector plate 59 remains in the central position to direct the object into the correct weight group.

Each selective setup of the relays I38, I42 and M8 is cleared at the start of the next cycle as the cam 90 operates the switch 88 to briefly open its contacts I3I.

The synchronization of the switches '81 and 88 in relation to the lever and loading slide movements is shown in the timing diagram shown in Fig. VI.

The solid line I54 is a plot of the position of the lever I8 for each instant of time during aeycle of operation. The straight portion represents the time during which the lever I8 is latched in its upper position and is being loaded. The curved portion, a cosine curve, represents its swing. The dashed line I55, rising sharply at the start of the cycle, represents the motion of the loading slide 43. The sharply rising portion corresponds to the forward loading stroke occuring while the lever I8 is latched, the next horizontal portion a period of rest to allow the lever to carry the object below the lips 52 of the slide 43, and the succeeding portions the return stroke and period of rest with the motor 51 stopped while waiting for the lever to complete its swing.

The next line I56 showsthe portions of the cycle during which the photocell is light. The interruptions when the lever is at the bottom of its swing are dependent upon the weight of the object. This linealso shows the time that the I relay H8 is energized.

The timing of the cam operated switch 81 is shown by lines I51 and I-58. The line I51 shows the portion of the cycle that contacts I23 are closed to energize the relay I and the selector solenoids 14 and 15 according to the previous selection. The line I58 shows the remainder of the cycle during which the contacts I21 are closed to energize the relay I2I and the lever latch solenoid I29. These latter elements, the relay I2I and the solenoid I29, may also be energized through contacts I of the relay II5 therefore they are energized as long as the photocell is light or the contacts 121 of the switch 81 are closed.

The remaining line I59 shows the operation of the switch 88 to clear the previous selection at the start of each cycle.

It will also be recalled that the motor '51 stops whenever the photocell is light while contactsI23 of the switch 81 are closed.

The sequence of events in a normal cycle of operation is:

First, with the motor 51 running and the lever I8 latched, the slide 43 moves rapidly forward to push the previously weighed object into the selector chutes and load the next object on the load receiver 25.

Second, after a brief pause, the cam 89 operates the switch 81 to close contacts I21 thus energizing the solenoid I29 to release the lever I8. Simultaneously, although not neces essarily precisely so, the cam actuates the switch 88 briefly to clear any previous selection set up on the relays I38, I42 and I48.

Third, after a pause to allow the lever to start to swing, the motor 51 begins to retract the loading slide 43.

Fourth, at the bottom of the swing of the lever I8 the vane 39 acting through the photo electric system sets up the relays I38, I42 and I48 according to the weight of the object.

Fifth, the cam 89 allows the switch 81 to return to its normal position to close contacts I23 thus energizing relay I25, and through the relays I38 or I48, the proper selector solenoid 14 or 15. Since the photocell is light at this time the motor 51 stops.

Sixth, as the lever I8 approaches its latched position the vane 38 interrupts the light, the solenoid I29 is deenergized to latch the lever, and through the relay I2I the motor 51 is started for the next cycle.

The device is adjusted to properly sort the objects by weight byselecting two of the objects whose weights define the upper and lower limits of the correct weight zone. With the manualautomatic switch I2 open to prevent operation of I the feeding and selecting mechanism, the lighter of the two selected objects is placed in position on the load receiver 25 and the push button I3 is depressed. Current then flows from the supply lead I05 through the contacts of the pushbutton I3, leads I28d, I28a and I280, the latch solenoid I29 to the return lead I04. The solenoid I29 then unlatches the lever I8. As soon as the lever starts to move and light enters the photo-cell 34 the push button may be released since the lead I280 is then connected throughthe contacts I30 of the relay III; to the branch lead I05a of the supply lead I05. The lever I8 is caught on its return in the usual manner.

As the lever approaches the bottom of the swing the vane 39 may or may. not interrupt the light to operate the relay H8. The balance weight 24 is adjusted by trial until the relay II8 operates on about half the swings of the lever I8 thus indicating that the vane 39 barely reaches the light beam.

Next with the heavier of the selected weights in position the sensitivity is adjusted. In this case, with the heavier weight, there should be one or two operations of the relay H8 depending upon whether or not the vane 39 passed the light beam. The pendulum weight 22 is adjusted by trial until the approximately equal occurrence of the one or two operations indicates that the vane 39 is barely passing the light beam.

As these adjustments are not completely independent successive adjustment may be necessary to satisfy simultaneously the required conditions of balance and sensitivity. 1

Modifications may be made to meet various requirements without departing from th essence of the invention as defined in the appended claims.

Having described the invention, we claim:

1. In a device for classifying objects according to weight, in combination, a pendulous lever, a load receiver supported by said lever, a stop for limiting movement of said lever at one end of its travel, a cam on said lever, a latch engaging said cam to push said lever against said stop, means for automatically removing a weighed object from and placing an object to be weighed on said load receiver while in latched position, means for unlatching said lever, means for determining the amplitude of swing of said'lever, means for releasing said latch as saidlever approaches said step to permit said latch to engage said cam to position said lever, and means for directing the weighed object into the proper receptacle according to its weight as determined by the swing of said lever.

2. In a device for classifying objects by weight, in combination, a pendulous lever, a load receiver supported by said lever, a stop for limiting movement of said lever at one end of its travel, a cam on said lever, a latch engaging said card to push said lever against said stop, means for automatically removing weighed objects from and placing objects to be weighed on said load receiver while in latched position, means for withdrawing the latch from the cam of said lever, a light source and photocell in cooperation with vanes on said lever for electrically indicating positions assumed by said lever durin its swing, electrical means for positioning a selector in accordance with the swing of said lever, said latch withdrawing means being released by signal from said photocell to permit said latch to catch said lever at completion of its swing.

3. In a device for classifying objects according to weight, in combination, a pendulous lever, a load receiver supported by said lever, a stop for limiting movement of said lever at one end of its travel, a cam on said lever, a latch engaging said cam to push said lever against said stop, a light source and photocell cooperating with vanes on said lever for electrically signalling positions assumed by said lever, electrical means for withdrawing said latch from said cam to release said lever and in response to signals from said photocell for releasing said latch to catch said lever at the completion of its stroke and sequence after the loading of said lever, a light source and photocell cooperating with spaced vanes on said lever for providing electrical indication of positions assumed by said lever, an electrically operated selector positioned in accordance with the amplitude of swing of 'said lever and means initiated by a signal from said photocell for latching said lever at the completion of its swing.

5. In a device of the class described, in combination, a load receiver suitably supported by a swingable weighing lever, a latch for releasably holding the lever at one end of its travel, a support containing in its upper surface a trough aligned with said load receiver when .the lever is latched, a slide over said trough moving in ways along said trough for positioning objects to be weighed along said trough and load receiver, springs for advancing said slide into loading position while said lever is latched, means for withdrawing the latch after the slide reaches loading position and a motor and cam for retracting said slide while said lever is completing a swing, whereby the swing of said lever removes the object to be weighed from the path of said slide before the retraction of said slide.

6. In a device of the class described, in combination, a freely swingable lever adjustable for balance and pendularity, a load receiver supported by said lever, a stop for limiting upward movement of the lever at the top end of its travel, a cam on said lever, an electrically controlled latch for engaging said cam to position said lever against said stop, a frame having a trough in its upper surface in line with the upper position of the load receiver, a reciprocably mounted slide over said trough adapted to intermittently push objects to be weighed along said trough and onto and from said load receiver. means for withdrawing said latch when said slide is at the forward end of its stroke to permit the lever to carry an object below the slide before the retraction of the slide, a light source and photo cell cooperating with vanes on said lever to provide electrical indication of movements of the lever, means responsive to signals from said photo cell to sort the weighed objects and to release said latch withdrawing means as said lever approaches said stop.

FRED W. GILCHRIST.

DONALD B.-KENDALL.

ROBERT O. BRADLEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,067,744 Williams Jan. 12, 1937 1,784,540 Ripley Dec. 9, 1930 2,051,695 Glacy Aug. 18, 1936 1,120,714 Hinsdale Dec. 15, 1914 

